Answer: 24 hours
Step-by-step explanation:
When the max CPC is manually overriden, the new max CPC will remain for 24hours, this would make the search Ads 360 optimization system not to update the max CPC during this time. After 24hours margin, the search Ads 360 will resume optimizing your bids inorder to meet the goals of bid strategy in turn starts the max CPC manually.